Thermococcus paralvinellae sp. nov. and Thermococcus cleftensis sp. nov. of hyperthermophilic heterotrophs from deep-sea hydrothermal vents.

TitleThermococcus paralvinellae sp. nov. and Thermococcus cleftensis sp. nov. of hyperthermophilic heterotrophs from deep-sea hydrothermal vents.
Publication TypeJournal Article
Year of Publication2014
AuthorsHensley SA, Jung J-H, Park C-S, Holden JF
JournalInt J Syst Evol Microbiol
Volume64
IssuePt 11
Pagination3655-9
Date Published2014 Nov
ISSN1466-5034
KeywordsAnimals, DNA, Archaeal, Hydrothermal Vents, Molecular Sequence Data, Pacific Ocean, Phylogeny, Polychaeta, RNA, Ribosomal, 16S, Sequence Analysis, DNA, Thermococcus
Abstract

Two heterotrophic hyperthermophilic strains, ES1(T) and CL1(T), were isolated from Paralvinella sp. polychaete worms collected from active hydrothermal vent chimneys in the north-eastern Pacific Ocean. Both were obligately anaerobic and produced H2S in the presence of elemental sulfur and H2. Complete genome sequences are available for both strains. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strains are more than 97% similar to most other species of the genus Thermococcus. Therefore, overall genome relatedness index analyses were performed to establish that these strains are novel species. For each analysis, strain ES1(T) was determined to be most similar to Thermococcus barophilus MP(T), while strain CL1(T) was determined to be most similar to Thermococcus sp. 4557. The average nucleotide identity scores for these strains were 84% for strain ES1(T) and 81% for strain CL1(T), genome-to-genome direct comparison scores were 23% for strain ES1(T) and 47% for strain CL1(T), and the species identification scores were 89% for strain ES1(T) and 88% for strain CL1(T). For each analysis, strains ES1(T) and CL1(T) were below the species delineation cut-off. Therefore, based on their whole genome sequences, strains ES1(T) and CL1(T) are suggested to represent novel species of the genus Thermococcus for which the names Thermococcus paralvinellae sp. nov. and Thermococcus cleftensis sp. nov. are proposed, respectively. The type strains are ES1(T) ( =DSM 27261(T) =KACC 17923(T)) and CL1(T) ( =DSM 27260(T) =KACC 17922(T)).

DOI10.1099/ijs.0.066100-0
Alternate JournalInt. J. Syst. Evol. Microbiol.
PubMed ID25082851